What Causes Hearing Loss
Hearing loss is often associated with advancing age, but this is not always the case. Although it can strike people at any age, the condition most often appears after the age of 65. It does however have many other causes, such as noise exposure, birth defects, infections, injury and medications to name a few.
The two leading causes of hearing loss are age and noise exposure.
1. Age-related hearing loss (presbycusis) is the loss of hearing that gradually occurs in most of us as we grow older. It is one of the most common conditions affecting older and elderly adults. It most often occurs in both ears, affecting them equally. Because the loss is gradual, you may not realize that you’ve lost some of your ability to hear.
2. Noise induced hearing loss is a permanent hearing impairment resulting from prolonged exposure to high levels of noise. When noise is too loud, it begins to kill cells in the inner ear. As the exposure time to loud noise increases, more and more hair cells are destroyed. As the number of hair cells decreases, so does your ability to hear.
Types of Hearing Loss
In general, there are three types of hearing loss: conductive, sensorineural or mixed hearing loss (a combination of both).
Conductive hearing loss is caused by problems in the outer and middle ear, which can prevent sounds getting through to the inner ear. The most common cause can be a build-up of wax in the ear canal, perforated eardrums, fluid in the middle ear, or damaged or defective ossicles (middle ear bones).
Sensorineural hearing loss happens when the delicate sensory cells or nerve fibres in the inner ear get damaged. This stops them transmitting sound properly. The most common causes of sensorineural hearing loss are the natural process of ageing or excessive exposure to noise. This condition is in most cases permanent.
How the ear functions
The human ear is a precisely tuned system with a sensitivity and range that easily outperforms the most elaborate sound system ever manufactured. The ear contains many physiological mechanisms, and a breakdown or disruption in any of these can result in hearing difficulties. Fortunately, in most cases you can improve your hearing by wearing hearing instruments.
The anatomy of the ear
The ear is made up of three different parts.
1. The outer ear: The shape of the outer ear helps to collect the sound waves and direct them through the auditory canal to the eardrum.
2. The middle ear: Contains the eardrum and three tiny bones: the Hammer, Anvil and Stirrup (also called the Malleus, Incus and Stapes). These amplify the sound waves.
3. The inner ear: Sound waves are changed into electrical impulses by the cochlea. There are tiny sensory cells along the entire length of the fluid filled cochlea. The cochlea transmits the message via the nerve fibres to the area of the brain in charge of processing and interpreting what we hear.
How we hear sounds
Sounds can be described as loud or soft, high-pitched or low-pitched. A violin, or birds singing are examples of high-pitched (or high frequency) sounds, while a double bass, or traffic in the street are examples of low-pitched (or low frequency) sounds.
How your hearing can change
Even with a hearing loss you might feel that life sounds just as loud as ever. Some sounds, like a lawnmower, remain audible while others become harder to hear. Take the voices of women and children, for instance. You will have to work doubly hard to follow what they are saying, as their voices are softer and higher pitched than men’s voices.
Our hearing gets weaker over the years, it basically starts to decrease before you become a teenager. It is a very slow process, therefore it is difficult to recognise. Knowing more about what to be aware of will help you monitor your own reactions: If you find yourself saying “What?” and “Sorry could you repeat that?” you will know that
it is time to take action and get your hearing tested.
Keeping up with speech
What makes speech so hard to follow with a hearing loss is that it involves so many different sounds in a rapid flow. The softer, high pitched consonants such as ‘f’, ‘s’ or ‘t’ can be drowned out by the louder, low-pitched vowel sounds, such as ‘a’, ‘o’ and ‘u’. So if someone says “statue” and all you can hear is “s_a_ue”, you will be forced to try and guess the rest…by which time the conversation will have moved on.
At meetings and social events there is nothing worse than having to ask people to repeat themselves. You might blame others for mumbling, when it is actually your hearing that is at fault. Communication will become increasingly difficult, until eventually you will withdraw from social situations completely.
Do a quick self check / Hearing Questionnaire
If you answer “yes” to some of these questions, it may be worth booking a test with your nearest Audiologist. It may just be a build up of earwax causing you to not hear so well but rather check it now before the problem gets worse.
Do people seem to be mumbling?
Do you have to strain to hear when someone talks or whispers?
Do you have difficulties hearing someone call you from behind or from another room?
Do you need to watch a speaker’s lips more closely to follow the conversation?
Do you find it hard to keep up in meetings, in restaurants, or in lectures?
Do you have to turn up the volume on the TV or radio?
Do you find it hard to hear clearly on the telephone?
Do you have difficulties hearing at the theatre, cinema or other entertainment venues?
Do you find it hard to hear in noisy environments like in the street or in a car?
Do you tend to limit your social activities because it’s difficult to hear and communicate?
Do family, friends, or colleagues mention that they often have to repeat themselves?